This investigation was opened based on three consumer complaints of electric seat warmer overheating in MY 2003 Mercedes Benz ml-320 vehicles.consumers alleged that such failures may inflict burn injuries to seat occupants.investigation disclosed that the identical seat warmer design was installed in 65.5 percent of all M-class vehicles produced during MY 2000-2005.the alleged defect resulted from breakage of the electrical bus wire of the heater grid in the outboard side of the seat bolster.the failures were caused by repeated high stress applied during occupant ingress and egress.a similar failure mode had been previously identified in investigations of this type of failure in other vehicles.the rates of complaints and warranty claims for the subject vehicles, as well as for other M-class vehicles with the same seat warmer design, were in some cases higher, but on the same order of magnitude as the rates seen in other vehicles investigated.the information disclosed that seat cushion damage was limited to small, localized areas and that no risk of fire existed.the injuries reported were consistently very minor in severity and at rates comparable to those seen on other investigations.ODI concluded that a safety-related defect trend was not identified in this matter at this time.accordingly, this PE has been closed.the closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist.the Agency reserves the right to take further action if warranted by the circumstances.
